On this same note I would also suggest some papers which show you can do so much better than simple erasure coding -

[1] Clay Codes - https://www.usenix.org/conference/fast18/presentation/vajha . This paper was also implemented on Ceph and the results are shown in the paper.

and, [2] HeART: improving storage efficiency by exploiting disk-reliability heterogeneity - https://www.usenix.org/conference/fast19/presentation/kadeko... . This paper talks about how just one erasure code is not enough and employing code conversions over the disk-reliability we can get up to 30% savings!